Ignition coil



H. L. HARTZELL IGNITION GOIL Filed Jan. 2, 1932 Patented Oct. 25, 1932 Y UNITED STATES ,PATENT OFFICE y HERMAN L. HARTZELL, OF ANDERSON, INDIANA, ASSIGNOR '10 DELOO-REMY CORPORATION, OF ANDERSON, INDIANA, A CORPORATION OF DELAWARE IGNITION COIL Application led Ianuary2, 1932. Seal No. 584,525.

This invention relates to ignition coils for use with internal combustion engines and one of its objects is to improve the conduction of heat from the windings of the coil to the exterior thereof.

A further object is to provide a coil having both ends of its secondary winding connected with terminals, located upon the non-conducting cover for the coil housing and to provide improvements in the manner of insulating the leads from the secondary winding from each other and from other parts of the coil. In this connection vit is a further objectto provide improvements in the 1| means for connecting insulated high tension f cables to the terminals of the secondary winding to keep these connections free from moisture which would tend to cause a short circuit.

Further objects and advantages of the present invention will be apparent from the following description, reference being had to the accompanying drawing wherein a preferred embodiment of one form of the 85 present invention is clearly shown.

In the drawing:

Figure l is a plan view of a coil embodying the present invention;

Figure 2 is a sectional view on the line $0 2-2 of Figure l;

Figure 3 is a plan view of the coil housing cover with the secondary terminal cover re- 'moved;

Figure 4 is a sectional view on line lr-l of Figure 3 with the secondary terminal cover in place;

Figure is ai'bottom view of the coil housing cover;

Figure 6 is a sectional view on the line @-.6 of Figure 5; l

Figure 7 is a plan view or a rubber gasket for sealing the joint between a high tension cable attached to a secondary terminal and the coil housing cover and the secondary terminal cover;

Figure 8 is an end view thereoi loolring in the direction of the arrow 8 of Figure 7;y Vand.

Figure 9 is a fragmentary view .ont a strip of sheet magnet iron used to form the outer magnetic circuit of the coil.

The coil assembly comprises a metallic tubular case 20 which is attached to the metal bottom 21 providing a ridge 22 which 55 lits into a recess 23 in a porcelain base block 24.- Before the base block 24 is assembled within the case 20, it is assembled with a secondary winding 25` which is wound upon a tube 26 and which is enclosed by convolutions 00 of paper forming a tube 27 which extends well above the upper margins of the paper wrappings 28 whlch insulate the layers of the turns of the secondary winding 25 and which extends downwardly to the lower end of the o5 margins of the wrappings 28. Upon this assembly of secondary coil 25 and paper tube 27 there is wound the primary winding 29 having leads 30 and 31 which are protected by sleeves 32 and 33 respectively. The as- 70 sembly of secondary coil 25, paper tube 27 and primary 29 are assembled with a central core 34 comprising a bundle of rods or plates packed snugly within the tube 26. This assembly of parts is assembled with the base 24 by applying to the base or assembly a coating of beeswax, or similar insulating compound 3.5, the parts being squeezed to-l gether before the beeswax hardens.

Before the coil core and base assembly is placed within the case 20, a rolled-up strip of magnet iron 40 is placed within the case and is then squeezed outwardly by suitable tools in order to press the convolutions of the strip l0 firmly against the interior wall of 65 the case 20 in order to prevent rattling of the strip 40 due to magnetic hum. As shown in Figure 9, the strip 40 is divided by a number or" parallel slits 4l terminating short of the end margins of the strip. The purpose or'l the so slits is to reduce eddy current losses. After placing the magnet iron within the case, a quantity oil pitch or hydrolene is poured into the bottom of the case, the quantity being, suiiicient to cause the level thereof te rise a substantial distance, preferably about halt way up the case; then the coil core and base block subassembly is introduced. After placing the coil core and base subassembly within the case the terminals of the coils are thread- -:i':

` will now be described.

The cover 41 comprises a body 42 of molded bakelite in which is embedded a metal ring 43 carrying an annular flange 44 whichas shown 1n Figure 2, is spun around the outwardly extending flange 45 of the case 20, as indicated at 46. The body 42 is provided `with adownwardly extending skirt 47 which encloses the upper end of the core 34 and one of the leads 48 of the secondary 25. The body 42 provides within the confines of the skirt 47 a hole 49 through which the lead 48 extends. The hole 49 continues through the base of a pointed metallic insert 50 embedded in the body 42. Hence the lead 48 is threaded through the body 42 and insert 50 before the cover 41 is `attached to the case 20. The other lead ofthe secondary 25 is not shown, but it will be understood that the wall of the body'42 between the outside of the skirt 47 and an arcuate apron 51 is provided with a hole 52, and that this lead is threaded through said hole 52 which extends through the body 42 and the base of a pointed insert 53, shown l in Figure 3. The primary leads 30 and 31 are threaded through holes provided in the body 42 and in the heads of .threaded metallic inserts 54 and 55 embedded in the body 42 to provide the primary terminals. The holes for the leads 30 and 31 are indicated at 30a and 31a respectively, in Fig. 5. Before the coil leads are threaded through the cover 41, a non-conducting tube 56 is placed around the coil assembly as shown in Figure 2, in order to further insulate the leads 30 and 31 from the case and to hold the outside iron 40 tightly against' the case.

After threading the leads of the coil through the cover 42 and before assembling the cover, a certain quantity yof hydrolene or other pitch is poured into the case 20 sufficient to bring the level of the hydrolene nearly to the top of the case, then the cover. is applied,

the leads are pulled through the case to draw them taut and the cover is attached to the case permanently by spinning over the flange 44, as indicated at 46 i`n Figure 2. The leads 30 and 31 are twisted once around the threaded Shanks of the terminals 54 and 55 and the single turn of these leads are each pressed into a grove 58 (see Fig. 2) provided in each of the inserts 54 and 55, solder is applied, and then the excess end portion of the lead which projects from the solder is cut off to leave the 'shoulder 59 of the insert as a plane surface forI receiving a washer 60 clamped by a nut 61. The leads of the secondary 25 are joined to the terminals 50 andl53 in a similar manner. As shown in Figure 2, the terminal 50 is Aprovided with'a groove 62; and, as'shown in Figure 6, the terminal 53 is provided with a groove 63; these grooves receiving one turn Referring to Figures 7 and 8, 70 designates a soft rubber gasket comprising a relatively thin, fiat web 71 carrying a rectangular rib 72 and connecting cross ribs 73, all located on one side thereof as shown in Figure 8. The web 71 is integral with tubular members 74 of such internal diameter as to t smoothly over the ends of rubber insulated high tension cables. The exterior diameters of the sleeves 74 are such as to fit smoothly within semi-cylindrical' recesses 75 provided by the cover body 42 and partly enclosing the pointed inserts 50 and 53 respectively, and iitting smoothly within mating semicylindrical recesses 81 provided in a cable cover 80,

terial of the same brand as the cover body 42.

Each rubber sleeve 74 is provided with arcnate rib portions 77 received by arcuate groovedportions 78 provided by the cover body 42 and similar arcuate grooved portions 82 provided by the cable cap 80, as shown in Figure 4. After the high tension cables have been inserted within the sleeves 74 and have been pushed against the closed ends of these sleeves, the gasket 70, together with the cables attached thereto, is placed upon `the cover body 42 and is pushed downwardly into position, as shown in Figures 2 and 4, thus causing the pointed inserts 50 and 53 to` pierce through the sleeves 74 and through the in-y sulation of the cables and between the wires of the stranded conductors of the cables, all

as shown inFigure-4. The cable cover 8() is attached to coil cover 41' by a screw 85 passof the cable cover 80 against the coil cover body 42 by turning the screw 85 will cause the rubber gasket to be squeezed to`fill out vall the vacant spaces which might exist between cover 80, cover body 42, and the cable 90 and thus prevents the entrance of moisture into the high tensioncable receiving sockets which are provided by the cable housing 80 and c oil cover body 42.

Referring to Figure 5, it will be noted that necessary precautions are taken to insulate the high tension leads which pass through the holes 49 and 52, from eachother. The lead passing through the hole 49 is insulated from the other leads and from the`\ case by the skirt 47. TheI lead passing through the hole 52 is insulated from the case by the apron 51. Y The leakage path between the lead passed through the hole 52 and the primary lead passed through the hole 30a is length- ,ened by a notch 57 provided in the inside wall of .the cover body 42.

The heat developed in the primary 29 'can thin surrounding layer of pitch and through the convolutions of magnet iron 40 which are pressed firmly against each other and against the interior wall of the case. It was the practice to wind the magnet iron 40 with a strip of paper in order that the turns of the iron would not touch each other. This was done to prevent noise due to magnetic hum, but it has been vfound that the magnetic hum can be eliminated without requiring the use of a layer of paper between the turns'of magv net iron provided the iron is firmly packed into place before the other parts are assembled.. By dispensing with the layer of paper between the convolutions of magnet iron, the thermal conductivity of the material between the pitch layer and the coil case has been materiallyl increased, thereby making it possible to maintain a lower coil temperature than heretofore. t

While the form of embodiment of the present invention as herein disclosed, constitutes a preferred form, it is to be understood that other forms might be adopted, all coming within the scope of the claims which follow.

What is claimed is as follows:

1. An ignition coil comprising, in combination, a tubular coil case, a non-conducting cover for the case, two primary terminalsand two secondary terminals carried by the cover, a skirt provided by the cover within the case, a central magnetizable core extending within the skirt, a secondary surroundingI the core and having leads separated by a wall of the skirt, a primary surrounding the secondary and having its leads connected with the primary terminals, and an apron depending from the cover to insulate from the case that secondary lead which is on the outside of said skirt.

2. A moisturegproof terminal for ignition coils and the like comprising, in combination,

' termina-l member,

the

-a nonconducting terminal member providing a groove, a nonconducting-cover attachable tothe terminal member and providing a companion groove, the two mating grooves providing together a socket adapted to receive an insulated wire, a pointed terminal extending transversely in the socket, and adapted to` pierce through the insulation of a wire, a gasket of compressible water-proof material, such as soft rubber providing a web located between the terminal member and cover and providing a tubular socket for recelving an insulated wire, and locatable within the socket provided by the-cover and Y and means for clamping gasket between the cover and terminal member in order to cause the gasket to be4 com ressed and to seal the joint between the ins ation of the wire and the cover and the terminal block.

3. A moisture proof terminal for ignition coils and the like comprising, in combination, a nonconducting terminal member providing a groove, a noncondu'cting cover atv tachable to the terminal member and providing a companion groove, the two mating grooves providing together a socket adapted toreceive an insulated wire, a member of compressible water proof material such as soft rubber providing a thimble which is slipped over the end of the insulated wire said thimble being received by sai-d socket provided by theterminal member and its cover, a pointed terminal extending transversely in the socket and piercing the thimble and wire insulation, and means for clamping the thimble between the cover and terminal in order to cause the thimble to be compressed and to seal the joint between the insulation of the wire and the cover and the terminal block.

' 4. A moisture proof terminal for ignition coils and the like comprising, in combination, a nonconductng terminal member providing a groove, a nonconducting cover attachable to the terminal member and providing a companion groove, the two mating grooves providing together a socket adapted to receive an insulated wire, a member of com ressible water proof material such as so rubber providing a thimble which is sli ped over the end of the insulated wire sai thimble being received by said socket provided by the terminal member and its cover, a terminal carried by the member and connected to the wire, and means for clamping the thimble between the cover and terminal in order to cause the thimble to be compressed and to seal the joint between the insulation of the wire and the cover and the terminal block.`

lin testimony whereof I hereto aiix my signature. i

HERMAN lL. HARTZELL. 

